Improved apparatus for forming threads on sheet-metal caps



' UNITEDn STATES PATENT OFFICE.

WILLIAM T. GILLINDER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO HIMSELFAND EDWIN BENNETT, OF SAME PLACE.

IMPROVED APPARATUS FOR FORMING THREADS 0N SHEET-METAL CAPS.

' Specification forming part of Letters Patent No. 71,605, datedDecember 3, 15367.

Y To all whom it may concern.-

Be it known that I, WILLIAM T. GILLIN- DER, of the city of Philadelphia,in the State of Pennsylvania, have invented a new and useful Improvementin the Mode of Forming Screw-Threads in Sheet-Metal Caps; and I dohereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawings, making a part of this specification, in Which- Figure 1 is aplan View of the forming-dies in the lower part of their case, the upperpart of the latter being removed for the purpose 5 Fig. 2, a likerepresentation of the same having the upper part of the case applied,and Fig. 3 a vertical section cut on the dotted line x y of Fig. 2, likeletters of reference indicating the same parts when in the differentfigures.

My improvement relates to the formation of the screw-threads in thesides of those sheetmetal caps which are used for closing bottles,

jars, &c. Heretofore the threads have been formed by spinning on alathe, and therefore by the expenditure of a great deal of labor and time; and the object of my invention is to reduce the labor, facilitate theoperation, and therefore to reduce the cost of their production.

It consists in producing the screw-threads in a sheet-metal-cap at asingle stroke by the pressure Vof dies operating substantially as,hereinafter described. l

Referring to the drawings, A A A A are the dies; B B,the bottom portionof the case, and G C theupper. portion of the case. The diesA arearranged inthe bottom Bof the case at right angles to each other, andbetween guides-btb', so that they can be movedV easily in the directionof their' lengths, and thus cause their'inner endstoapproach toward andrecede from eachother, (see Fig. 1,) their inner ends, a et', beingcurved, and provided with screw-threads, so that when brought together around hole will be left between the said screw ends, which will be abouttwice the depth ofthe said threads, less in its diameter than thediameter of the cap which isto be operated upon. (See Fig. 3.) The upperside of each of the die-blocks A has a projecting stud, c, whereby theycan be moved backward and forward by means of with the diesA. (See lthefaint lines c c in Fig. 3.)

The upper part, O, o the case has a round holein its center, whic' isabout twice the diameter of the hole between the closed dies A, and hasalso four'eccentric slots, c cl c c", which respectively receive Vthefour studsva. of the saiddies when C is applied over B, as shown inFigs.'2 and 3, the said eccentric slots being curved, so as to canse thedies A to close `andopen as the said part/G is rotated'right and left,alternately, upon B.

The part B is intended to be iirmly iixed in a strong frame and the partG applied upon it, as shown in Figs. 2 and`3, so that the latter can berotated right and left by means of any suitable hand-lever or arm fixedthereto (not shown iu the drawings) in such a manner that the dies Awill be moved powerfully toward and from each other alternately.

In operating the machine to thread-screw a cap, theV latter is to beplaced in the hole in the center of part G of the case, and so asto fitVdown over or upon the screw-plug, which has previously been inserted inthe central hole, b,`of the part B for the purpose, (see the faint linesc o, Fig. 3,) where itis to be held downirmly by means of any suitablevertically-moving bar or other device, (not showin) to be attached tothe frame of the machine for the purpose, when the' operator causes thedies A to close suddenly and powerfully upon the cap and thusproducefthe screw-threads requiredthereon.- l An opposite movement givento @withdraws the dies A, and the finished cap springs open enough toallow of its being easily unscrewed by the tingers of the operator inremoving, thus forming the screw-threads upon the cap by a single strokeof the dies, and removing the finished Ycap in the most rapid and easymanner.

The dies A and the corresponding soreW- The apparatus herein describedfor swaging plugs are changeable for other sizes of threads,screw-threads on sheet-metal caps, substanas the different-sized caps tobe screwed may tially as set forth.

require. WILLIAM T. GILLINDER.

Having thus fully described my invention, Witnesses:

what I claim as new, and desire to secure by BENJ. MORISON, LettersPatent, is- WM. H. MORISON.

